Interchangeable screen construction for mill



July 26, 1960 c. E. PHILLIPS 2,946,523

INTERCHANGEABLE SCREEN CQNSTRUCTION FOR MILL Filed July 1a, 1955 5 Sheets-Sheet 1 FIG. 1

* INVENTOR.

C'll/IRL EJEPH/LL/PS B Y m/WW ATT'aR/VE YJ July 26, 1960 c. E. PHiLLIPS 2,946,523

INTERCHANGEABLE SCREEN cons'mucnon FOR MILL Filed July 18, 1955 5 Sheets-Sheet 2 IN V EN TOR. Cf/flRLES E. Pfl/LL/Ps IBM-(W July 26, 1960 c. E. PHILLIPS 2,946,523

INTERCHANGEABLE SCREEN CONSTRUCTION FOR MILL Filed July 18, 1955 5 Sheets-$heet 4 I06 /08 ll;

F1617, F768 F169 IN VEN TOR. C/mRLEs/i P/i/LL/PJ ,47- TORNE Y6 2,946,523 Patented July 26, 1960 United States Patent Ofiice INTERCHANGEABLE SCREEN CONSTRUCTION FOR MILL Charles E. Phillips, Downsville, Wis., assignor to The .Strong-Scott Manufacturing Company, Minneapolis, Minn., a corporation of Minnesota Filed July 18, 1955, Ser. No. 522,749 Claims. (Cl. 24'189) This invention relates to new and useful improvements in mills for the grinding or comminuting of materials and more particularly relates to mills of the hammertype having readily interchangeable screen construction.

In the grinding of various materials, particularly in the grinding of grain for, feed, itis conventional to use a hammermill grinder having rotating hammers and a circumferential screen. These mills are many times used in grinding small lots or runs and the degree of fineness of the different runs varies considerably. The degree of fineness is controlled by the peripheral screen and when finer or coarser grinding is desired, the screen is changed. It is to this problem of screen change that this invention is directed.

The hammermill type grinders are conventionally used in feed mills or grain elevators and conventionally operated, controlled and fed from one floor while the grinding itself is done on a successive or lower floor. The problem of screen change has been quite cumbersome inasmuch as it necessitates a descent and return from the lower floor each time a change is made.

Some attempts have been made to solve this problem of screen change but none has been wholly satisfactory.

The present invention is therefore designed to provide a new and useful screen structure for a hammermill and apparatus for ready and satisfactory interchange of various screens; to provide a new and useful screen structure in a hammermill; to provide a new and useful screen supporting carriage; to facilitate use of any one of several grinding screens for coarser orfiner grinding in a hammermill; to facilitate changing screens from a remote location; to facilitate reversing the screens in a hammermill grinder so as to grind on both sides of the screenfora maximum screen life; to facilitate the replacement of a damagedscreen section; to facilitate the obtaining of increased grinding capacity; and to provide compact storage for its screens not in use in the mill.

Other and further objects of this invention are those inherent and apparent in the apparatus as described, pictured and claimed, and will be developed as the description proceeds. 7

To the accomplishment of the foregoing and related ends, this invention then comprises the features hereinafter fully described and particularly pointed out in the claims, the following description setting forth in detail certain illustrative embodiments of the invention, these being indicative, however, of but a few of the various ways in which the principles of the invention may be employed.

This invention will be described with reference to the drawings in which corresponding numerals refer to the same parts and in which:

Figure 1 is a. vertical sectional view through a hammermill structure embodying the instant invention.

Figure 2 is a vertical sectional view taken along the line and in the direction of the arrows 2--2 of Figure 1;

Figure. 3 is a view similar to Figure 2 but showing means for storing the individual mill screens and showing the mill carriage in open position;

Figure 4 is an elevational view of the carriage lock means; I

Figure 5 is a fragmentary elevational view of an operator handle means for manipulating one of the screens;

Figure 6 is a plan viewof one of the screens of the instant invention;

Figure 7 is an enlarged fragmentary view,'partially broken away, of the screen of Figure 6;

Figure 8 is an end elevational view, partially in section, of the screen of Figure 6;

Figure 9 is a view similar to Figure 8 but showing a modified form of screen construction; a

Figure 10 is a horizontal sectional view taken along the line and, in the direction of the arrows 10-10 of Figure 3; and

Figure 11 is a view similar to Figure 2 but showing a modified; form of screen carriage.

Referring now to the drawings and, particularly to Figure 1, the mill generally designated 15 is supported upon a pair of base channels E16, which also serve to support the plate 17 upon which the motor, (not shown) is supported as well as the air inlet shield 18.

The plate 17 is secured to the top flanges of channels 16, and terminates at the vertical side plate 19, also secured to the channels 16 and a declined discharge pan or trough 21 is positioned between side plates 19 and 20. Air may be admitted to the machine through apertures 22, the amount of air flow being controlled by the gate 214, and the air will flow from left to right through the machine as indicated by the arrows 25' and emerge through the aperture 26 alongwith ground material, which aperture 26- is ordinarily connected to a fan duct (not shown). I

An angle support 27 isjoined to the top edge of each of plates 19 and 20 and each is strengthened by reinforcing gussets 28. On each one of the supports 27 isfastened a pillow block bearing 29 in which the ends of shaft 30 of the rotor assembly 31 are journalled. Thus, the pillow blocks 29 serve to support the shaft 30 for rotation therein. At the left end of shaft 30 with reference to Figure 1 thereis provided a motor coupling 33 which couples the shaft 30 to the shaft 34 of a motor, not shown, whereby the shaft 30 and consequently the. rotor assembly 31 may be rotated. The rotor assembly is provided with a plurality of hammers 35A pivoted thereto and supported from spider 32. The rotor assembly will not be explained in greater detail since it forms no part of the invention per se. Joined to, supported on and forming a continuation of plates 19 and,.20. respectively are top end plates 35 and 36 which together with plates 19 and 20 form a closure for the mill. Reinforcing angle members 39 are situated along the junctures thereof as shown in Figure 1. v

. Plates 35 and 36 terminate at 37 at which terminal-edge is usually attached-a chute or hopper for delivering materialv such as feed or grain into the mill. A reinforcing angle member 38 extends along each terminal edge 37 and provides a horizontal connecting flange to. which a hopper or chute may be secured. Also as will be seen with reference to Figure 2, the edges of plates 35 and 36 are inclined as at 45 for plate 36.

As shown in Figure 2, the mill 15 is also provided with a front plate 40 and a back plate 41 each having top and bottom horizontal flanges, the bottom horizontal flanges .resting on and joined to the top flanges of channels 16 and the top flanges serving to support front and back cover members 42 and 43.

Theback cover 43 comprises an arcuate portion 46 having a flange 47 normally positioned at an incline to the horizontal when the back cover 43 is in the position of Figure 2, a second flange 48 positioned in the horizontal and resting upon the top flange of back plate 41, and side flanges 49 having edges cooperating with edges 45. The back cover may be held in position by any suitable means, usually bolts through the flanges so that ready removal is provided for access to the machine.

The front cover 42 is provided with an arcuate portion 50, a flange 47 and side flanges 51 of the configuration shown best in Figure 2, and a terminal edge 50A. The front cover is likewise held in position by bolts through the flanges.

Transverse members 45A united with plates 35 and 36, cooperate with the front and back covers 42 and 43 to provide complete closure of the front and back of the mill. Members 45A each have a top horizontal flange 46A for cooperation with the horizontal flanges of angle members 33, and an inclined flange 47A for cooperation with angle flanges 47. Flanges 47 are bolted thereto.

The bottom part 52 of a rectangular screen housing 52-53 has a configuration as shown best in Figure and is provided at its front 56A with a horizontal flange 54 resting upon and bolted to the horizontal flange of plate 40, and inclined terminal side edges 55 resting upon the inclined edges 45 of plates 35 and 36. The back member 56B terminates at 57 as shown. The bottom housing 52 is also provided with a guide or deflector plate 58 declined as shown in Figure 2 and secured to the front 56A and sides of housing 52. As shown in Figure 10, both the top and bottom housings 53 and 52 have a rectangular horizontal cross-section and are divided by strip separators 59 to provide ways in which the screens 6063 may travel. The housing 52 is provided with peripheral members 65 providing a horizontal flange which cooperates with the horizontal flange of peripheral members 65A positioned on the bottom of housing 53 whereby the top and bottom housing 53 and 52 may be bolted or otherwise secured together and in alignment.

To the arcuate underside of each of portions 46 and 50 there is secured an arcuate retarding plate 66 having a plurality of apertures 67 as shown in Figures 1 and 2.

The screen supporting carriage generally designated 68 is positioned within the mill as shown in Figures l-3. The carriage 68 is pivoted to and suspended at its back end from a rod 69 which rod is fixed to the plates 35 and 36. Hangers 70, one adjacent each wall 35 and 36, have joined thereto a flat cross brace 71 at the top edge of which is positioned a screen stop bar 72 extending thereacross. Also secured to each hanger 70 is an armate supporting member 74 positioned exterior thereof and joined thereto as shown in Figure 2. A third member 74 is centered therebetween and secured to the cross brace 71.

The arcuate member 74 is joined to and supports an arcuate screen support 76 shown in Figure 1 of expanded metal and having rhombic apertures therein.

One end of the screen support 76 is positioned to overlie the cross brace 71 and the other end is positioned to overlie one of each of the members 77 forming a hinge 7778 as shown in Figure 2 and subsequently explained. To the other end of each one of the members 74 is secured a hinge element 77 which cooperates with a corresponding hinge element 78, one of each pair of elements 77 and 78 forming the hinge, being positioned on one side of a member 74 and the other being positioned on the opposite side of a corresponding member 74A as shown in Figures 1 and 2. Each pair of elements 77 and 78 forming a hinge is pivoted about a common hinge pin 79.

Members 74A, three in number, one corresponding to each of members 74, likewise serve to support an arcuate expanded metal screen support 76. Joined to the nonpivoted ends of members 74A is a bar 81 having integral angle lugs 82, one at each end thereof, for cooperation with the plate 58 to guide the screens into position when the carriage is opened as subsequently explained. Each one of the free ends of the two outer members 74A is also provided with a reinforcement plate 83 through which hinge pin 84 is passed. Pin 84 also passes through an aperture in the center member 74A. Pivoted to pin 84 and adjacent each of the exterior members 74A is a link 85 adjustably secured to a pivoted eye-bolt 86,

in turn pivoted on the triangular plate member 87, each of which is in turn pivoted on a common pin 89 secured to the plates 19 and 20, as shown for plate 19 in Figure 2.

An operator bar 90 for each of the members 87 is joined at one end to a member 87 and at the other end by a common pivot pin 90 to a yoke 92 having a horizontal connecting member 93 to which is secured carriage control rod 94.

A carriage stop 95 is positioned as shown in Figure 2 and joined at its ends to plates 19 and 20.

As shown best in Figures 1 and 2, each side of the mill 15, formed by cooperating plates 19 and 35, and 20 and 36, is provided with a circular guide having a vertical flange secured to its respective machine side and an annular flange directed inwardly toward the center of the machine. It is against this annular flange that the retarding members 66 seat and a screen section S seats when in engaged position as subsequently explained.

\Figure 3 shows the vertical extension of the top housing 53, having terminal angle members 101, secured by vertical flanges to the housing and having horizontal flanges positioned to the underneath of the work floor 103. A floor plate 102 is provided and secured to the horizontal flanges of members 101 by bolts, and is usually rectangular in configuration. It is provided with a rectangular aperture 102A positioned so as to provide an edge 104 upon which each one of the lugs 105 for screen control rods 106 may engage when the screens are in the retracted position as shown in Figure 5. The aperture 102A extends leftwardly with reference to that figure, so that the screen rod 106 may be pivoted leftwardly so that lug 105 may disengage from edge 104 and the screen lowered in the top housing 53.

Each screen control rod 106 is provided with a handle 107, and is pivoted at 108 to screens S as shown in Figure 5.

The carriage control rod 94 also extends through an aperture in the work floor 103 as shown in Figures 3 and 4, and is pivoted at its top end by link 94A to gusset 109 of operator handle 110.

A lug 113 is provided on the stand 112, secured to work floor 103, for limiting the movement of the lever 110 from the full to the dotted line position of Figure 4, as it is moved around pivot 111 on stand 112. It will be seen with reference to Figure 4 that the pivot 114 passes to an over-center position as the lever 110 is moved from the full to the dotted line position, in the direction of the counterclockwise arrow. Thus, by engagement of the lever 110 with lug 113 maintains the lever in a locked or over-center position to lock the carriage 68 in the position of Figure 2. Pivot 88 also assumes an overcenter position as shown in that figure.

In Figure 3 the rod 94 and carriage 68 are shown in the position they assume when the handle 110 is in the position of Figure 4 (screen change position), and in Figure 2 the carriage 68 and rod 94 are shown in the position they assume when the handle 110 is in the dotted line position of Figure4 (screen lock position).

Each of the screens S is identical with the exception of the size of the apertures and will be explained on the basis of such identity.

Figures 6, 7'and 8 show the modification of the screen now about to be discussed. Thus, there is provided the screen S having a series of plates 115117. To plate -115 is pivoted the rod 106 by pivot 108 located substantially in the center of the screen for uniform balance. The plates 115 and 116 in this instance are shown as not being apertured-this being the only way in which they differ from plates 117. However, it is to be understood that these plates may be apertured as desired. Further more,'althoug'h each of the plates shown is provided with 'a plurality of apertures 118 comprising small diameter round holes, it is to be understood that other diameter holes may be and are used and'that other configurations may be used to provide the screen sections, thus square holes, oval holes, etc., may be used.

Each one of the screen sections 117 comprises a screen plate having notched corners as at 119, and at each end of which is secured a hinge loop 120. Hinge, loop 120 comprises two plies, one on either side of the screen plate as shown in Figure 8. At one end the hinge loop is provided with an extending tongue 121 and at the other end with a clevis providing groove or recess 122. The tongue of a succeeding loop cooperates with the recess or groove of a preceding loop, the tongue and the clevis forming the groove both being apertured to receive a hinge pin v123. Thus, each one of the sections 117 is hinged or articulated to a previous section as in Figure 7.

In the modification shown in Figures 1-8, the screen sections 117 are flat or planar. In the modification shown in Figure 9, screen sections 1 17A are each provided with a ridge or crimp 118A at the center thereof so that when the screens are in the position shown in Figure 11, they more nearly approach congruency with the circumference of a true circle. 7 i

As will be noted with reference to Figures 3 and 11, the first two screen sections 115 and 116 usually serve as articulated followers or links to position and disengage .the'screen from engagement with the carriage and are without apertures. p i

In Figure 1-1, a slightly different form of screen carriage 68A is shown. In this modification, the hangers 70,

and the cross-brace 7.1 are provided with a narrow screen stop barf/2A approximately half the thickness of bar 72 of the modification of (Figure 1. Thisbar is provided with an integral crimped guide .125 extending thereacross, which guide abuts the edge of the retarding plate 66 and under which the edge of end screen 117A is to be positioned. To the brace 71 and at the ends thereof is secured a pair of supporting rims 126, having indentations or crimps 127 therein. Crimps 1-27 are located so that when a screen 5 is in the position of Figure 11, one will overlie each hinge joint and onewill overlie each corresponding crimp in the screen.

Atalternate. crimps the members 126 are joined by pipes .128, the pipes being recessed to receive the members .126 which are welded thereto. The left end of each member126. (Figure .111.) ismade with a turned end 82A which serves the same function as the lugs 82 of the modification shown in Figure .2.

A brace .130 similar to brace 71 joins the other ends of members .126, and at each end thereof there is attached a hanger 1 31 to which is pivoted a link 1-32, the other end of the link 132 being pivoted at 133 to link 90. The pins .133 and 134 are common pivot pins for both links 1 32 and 90 respectively. -Also pivoted on pin 133 and resting upon pin 89 are supports 133A which function when the carriage of Figure 1!]. is in the dotted line position to engage one of the pipes 128 to support the carriage in this open position.

The operation of this mill will first be described with reference to the modification shown in Figures 1-8 and 10.

In operation, the mill is positioned with a screen in place and locked as shown in Figure 2 for screen S. Thus, in Figure 2, the screen S is positioned so that the sections 117 are in engagement with the flange 100 and the edge of the end section 117 abuts stop plate 72. In this position the screen sections 117 assume a position roughly corresponding to the circumference of a circle and about flange 100. The screen rod 106 for screen S has its lug 105 disengaged from edge 104 and the entire rod including the handle 107 is depressed to the position illustrated in Figure 3. The remaining screens 8 -8 and their respective rods are in the positions shown with the lugs of control rods 106 cugaging the edge .104 as shown in Figure 5.- The carriage 68-is maintained tightly in position against the :screen sections (Figure 2) and lugs 82 are in abutment therewith. The carriage is locked in this position by the cooperation of links 85,86 and 87 and the over-center position of pivot 88 maintains such locked position, together with the overcenter position of the pivot 111 since handle 1 10 will be in the dotted line position of Figure 4.

When it is desiredto change the screen the mill will 'be stopped, the handle moved from the dotted to the full line position of Figure 4 and through rod-94, the pivot 88' will be moved from the position of Figure 2 to the position of Figure 3, thus through cooperation of links 85, 86 and 87 allowing the arcuate supporting mem-- bers74 and 74A to assume the position of Figure 3, whereupon the member 74 is supported on the carriage stop 95. In this position the handle 107 for the screen S may be grasped and pulled upwardly, meanwhile being pivoted about pivot 108 .(slightly leftwardly with reference to Figure 5) until lug .105 passes edge 104 whence the'rod 106 may be returned to vertical position and lowered until lug 105 engages edge 104 whereupon the screen 8, will be maintained in retracted position. The 'lugs'82 and plate 58 will serve to guide the withdrawal of the screen 8,. Any one of the handles 107 for any of the screens S -S may thenbe grasped and moved leftwardly with reference to Figure 5, thus disengaging the lug 105 from the edge 104 and the screen will then sure {on handle 107 ifdesired, into position. i

The edge of the end screen 117 will engage plate 58 and through cooperation with lugs 82 and may be pushed around the channel for-med by flanges-100 and arcuate members 74 and 74A until the edge of the end screen 117 abuts the stop plate 72 as shown in Figure 3. This screen may then be locked in the position of Figure 2 bythe movement of the handle 110 from the full to the dotted'line position of Figure 4. a 1 The operation of the modification shown in Figure 11 is identical with that explained with the exception that there is no center pivot for carriage 68A corresponding -to pivot'g79 Further, there is no'toggle similar to that formed by links 85, 86 and 87. In this'modifica'tion, the

drop by gravity or may be assisted by a downward prescarriage 68A swings from the full to the dotted line posisupported by members 134 and there is no carriage stop 95. Further, intliismodification, the carriage 68A is retained in-position solely by the over center movement or the pivot 111 as handle 110 is moved from the full to the dotted line position of Figure 4.

In addition the crimps of'the screens 117 are positioned to engage the crirnps of the members 126.

As many widely differing embodiments of this invention may be made without departing from the spirit and scope thereof, it is to be understood that the specific embodiments described are given by way of example only and the invention is limited only by the terms of the appended claims.

What is claimed is:

l. A mill having a housing and a rotary member journalled within said housing, a circumferential screen removably positioned about said rotor, an arcuate carriage means pivoted for movement from a first to second position to retain said screen in said circumferential position, and said carriage means comprising a plurality of spaced arcuate members provided with a reticulated screen supporting surface.

2. In a mill having a housing and a rotary member journalled within said housing, the improvement comprising a circumferential screen having a plurality of planar sections hinged together and slidably and removably positioned substantially arcuately about said rotor, an arcuate carriage means pivoted for movement from a first spaced position to asecond screen engaging position to immobilize. said screen, and said carriage means providinga plurality of linear portions for engaging .corresponding planar sections when in said screen engaging position. a

3. A mill screen comprised of multiple hinged together units, at least some of said units comprising a flat perforated section having a crimp forming adjacent planar portions.

4. In a mill having a housing, a rotor journa'lled for rotation within said housing and an arcuate screen section positioned around a portion of said rotor, the improvement comprising a carriage assembly for supporting said screen section in position, said carriage assembly including a reticulated metal support. 5. In a mill having a housing, a rotor journalled for rotation within said, housing and an arcuate screen comprising a plurality ,of articulated members positioned around a portion of said rotor, the improvement comprising a carriage assembly for supporting said screen in position, said carriage assembly including a plurality of spaced members joined by parallel transverse members, said parallel transverse members being spaced one to overlie each of the junctures of said articulated members.

6. In a mill having a housing and a rotor within said housing, the improvement comprising an articulated circumferentially extending screen having a plurality of perforated planar screen members each hinged to adjacent screens.

7. In a mill having a housing and a rotor Within said housing, the improvement comprising an articlulated circumferentially extending screen having a plurality of perforated planar screen members each hinged to adjacent screens; each perforated planar screen member is provided at opposed edges with a hinge loop provided with an extending tongue atone end thereof and an extending clevis at the other end thereof, and pin means joining cooperating tongues and clevises on adjacent screen members to form hinges.

8. In a mill having a housing and a rotor within said housing, the improvement comprising an articulated circumferentially extending screen having a plurality of perforated planar screen members each .hinged to adjacent screens; each perforated screen member is provided with notched corners, and hinged means situated in said notched' corners.

9. In a mill having a, housing and a rotary member within said housing, edge portions of said rotary member committing a circular path of rotation during rotation of said rotary member, a screen positioned in substantially arcuate position about a portion of said circular path of rotation and spaced slightly therefrom, said screen comprising a plurality of sections, each section of substantially linear extension, means. articulately connecting said sections, extending operator control means secured to one end of said screen, a first substantially tangentially extending guide means for guiding said extending screen into extended position in which one end thereof is positioned substantially adjacent the periphery of said rotary member and the other end is remote therefrom, and means for maintaining said screen in said arcuate position, said last named means comprising a second guide means cooperating with said first guide means whereby said screen will be guided from said extended position to said arcuate position.

10. The structure of claim 9 further characterized by a plurality of such screens and said first mentioned guide means comprising a retaining means extending in an upward direction from said rotary member for retaining and supporting said plurality of screens therein.

References Cited in the file of this patent UNITED STATES PATENTS 669,508 Collier Mar. 12, 1901 681,983 Schoellhorn Sept. 3, 1901 836,163 Williams Nov. 20, 1906 1,165,541 Schmidt Dec. 28, 1915 1,695,371 Felde Dec. 18, 1928 1,721,289 Addicks July 16, 1929 1,759,448 Frickey May 20, 1930 1,795,792 Nielsen Mar. 10, 1931 1,861,471 Frickey June 7, 1932 2,023,604 Lovejoy Dec. 10, 1935 2,076,297 Gray Apr. 6, 1937 2,098,480 Ammon Nov. 9, 1937 2,149,571 Battey Mar. 7, 1939 2,360,892 Rench et a1. Oct. 24, 1944 2,640,650 Jacobson June 2, 1953 2,669,396 Nickle Feb. 16, 1954 2,710,149 Bryant June 7, 1955 2,734,687 Draves Feb. 14, 1956 2,771,249 Schutte Nov. 20, 1956 FOREIGN PATENTS 1,819 Great Britain 1909 3,950 Great Britain 1880 67,760 'Austria Feb. 10, 1915 89,452 Sweden Apr; 8, 1937 704,853 Germany Apr. 8, 1941 

